THE MEDITERRANEAN NATURALIST 
311 
means of increasing the tension and pressure in the 
magma, seems at present unanswerable. 
Anorthite was the most easily obtained, and 
corresponded iii characters exactly with the same 
mineral in lavas that have consolidated near the 
surface. This mineral, as is well known, is rarely 
met with in true plutonic rocks. 
(; to he continued.) 
Th? Collection and Preparation of 
Foraminifera. 
By Edward Halkyard, F.R.M.S. 
I propose in the present paper to describe as far 
as I am able the various methods employed in the 
collection and preparation of sand and other de- 
posits containing recent or fossil Foraminifera. 
The processes treated of will be chiefly those which 
I use myself in this work, but I may have occasion 
to mention, and in some cases quote, “in extenso,” 
various authors who have written on this subject 
from time to time. 
The apparatus required for the collection of 
shore-sand is very simple and inexpensive, consis- 
ting only of the following articles: a common iron 
spoon, a flat piece of tin turned up on three sides 
(the lid of a rectangular tin box with one end cut 
off 1 ’Eng very suitable), and a few small brownbol- 
laiid 1 bo contain the gatherings. The spoon is 
used for the purpose of scraping up the Foramini- 
fera from ripple-marks, the bottom of small pools, 
and other [daces where the sand is in a wet state. 
Thu tin plate will be found very. useful for scraping 
a level surface at high-water mark where the sand 
is in a drier state. I have several times, by means 
of this instrnnn nt, secured an almost pure gather- 
[U ® e oi Fo i mi f ;r ha ting dried 
sooner under a warm sun than the sand on which 
they were laid, the sand also being firmer and more 
compact than the lighter shells. Care must be 
taken not to scrape too deeply, for nothing except 
heavy baas w ill be gained by so doing, as the shells 
all lie upon the surface of the sand. I may here 
mention that I have found the time of low-water 
to be the best for collecting, as the sand is drier 
from being exposed to the air some hours, and the 
material gathered not containing so much water is 
in a fitter state for carrying in the collecting-bags 
without parting with surplus water in the form of 
drippings which generally find their way on to the 
collector’s clothes. 
The “set” of the tide and contour of the shore 
ought to be observed, as these are important fac- 
tors governing the place of deposit of the objects 
sought for. Shores where there are quantities of 
shingle at spring high-water mark ought to be 
visited if possible during neap tides, as there will 
generally be found a sandy lower shore, where the 
Foraminifera have a chance of being deposited by 
the retiring tide in a manner favorable for gather- 
ing. The collector ought not to neglect sear ching 
round the base of any large boulders, especially if 
there has not been any great “wash” about them. 
Zoophytes and small sea- weeds may also be exa- 
mined, in order to obtain parasitic forms which 
may be adhering to them, it is best to carry this 
material home and look at it when dry, the sand 
which is shaken from it being also put on one side 
to be “floated” with the other gatherings. I have 
also obtained good and rare species of Foraminifera 
from the sand and mud adhering to molluscs, Cru- 
stacea, etc., brought up by the trawlers, but it is 
only rarely that one is fortunate enough to come 
across a trawler who will take the trouble to save 
the rubbish from his trawl even though offered a 
good price for it. 
Living Foraminifera may be found by washing 
in a fine muslin net the small sea-weeds and 
Zoophytes growing in low-tide pools. The manner 
of using the net is as follows: a quantity of weeds, 
etc., having been gathered, the net is immersed in 
a pool (care must, however, 'be taken that the up- 
per edge of the net is kept above water), the weeds 
being washed one by one inside it, after this is 
done the contents of the net are turned into a large 
widemouthed bottle full of sea-water for exami- 
nation on the return home. Of course many other 
organisms besides Foraminifera will be found in 
this gathering, such as Ostracoda, Entomostraca, 
Copepoda, and other small crustaceans, which do 
not make the work any the less interesting. 
The Foraminifera ought to be picked out and 
put in sea-water in small bottles or tabes, when 
they will creep up the sides of the receptacles by 
